Dammit, Hydra! A fan who attended the Marvel Event leaked a scene from Avengers: Age of Ultron that may prove to be pivotal to the development of the relationship between Iron Man and Captain America:

The quality isn't great, but the content is exciting, as this clip deftly illustrates the reasons why Iron Man and Captain America will eventually be on opposite sides of a bitter civil war. Their ideological differences are clear, with Captain America determined to wear the white hat and "do the right thing" at all times, while Iron Man believes in occasionally indulging one's dark side for the greater good.

Here's a particularly telling exchange (especially for those of you who don't get a chance to watch the video before it's taken down):

Iron Man: "Isn't that why we fight the war, so we can end the war? So we can go home?"

Captain America: "Every time people try to win a war before it starts, innocent people die."

They're presumably referring to Tony's desire to build Ultron and relieve the Avengers of their duties. We, of course, know this to be an ill-advised idea, as Ultron is the villain of the piece, although to be fair, Tony may not have any reason to believe that would happen at this juncture.